Effects of Saline-alkali Stress on Seed Germination and Seedling Growth of Muskmelon

【Objective】 To analyze the effects of different levels of salt stress on the growth of muskmelon from two stages of seed germination and seedling development, and to provide theoretical basis for the screening of salt-tolerant resources of muskmelon. 【Method】 Four muskmelon varieties were used as experimental research materials, three treatment concentrations were set, and salt stress treatment was carried out at seed germination stage and seedling stage, respectively, to study the effects of different concentration of salt treatment on seed germination, seedling growth and root morphological characteristics. 【Results】 The germination rate and germination potential of the four melon varieties under low salt stress could maintain more than 50% and 60%, but the germination potential and germination rate under high salt stress showed significant decrease.The comprehensive germination index of melon varieties was reticulated Wangwenxiang>Fengwei5>Xizhoumi 17>Huangpi 9818. At 150 mmol/L salt concentration, Huangpi 9818 was significantly inhibited, and its germination rate was 49.8% longer than that of CK. Plant height, stem diameter and aboveground/below biomass accumulation of all melon varieties showed a decreasing trend with the increase of salt stress concentration, and had a significant negative correlation with high salt concentration. However, the inhibition of Wangwenxiang was the least under the same concentration treatment.Under salt stress, the root-shoot ratio of the four kinds of muskmelon showed a trend of decreasing first and then increasing with the increase of concentration, and it was significantly higher than that of CK under high salt concentration. The salt sensitivity index and tolerance index of each melon decreased, especially the tolerance index decreased significantly when the concentration was 100 mmol·L^-1, indicating that the sensitivity of the four melon varieties to high salt stress increased, and their salt tolerance decreased.Under salt stress, the root morphological parameters of four kinds of muskmelon were basically the same, all showed a downward trend, and the difference was significant compared with that of CK. 【Conclusion】 The comprehensive performance of Wangwenxiang was better than the other three varieties in the seed germination and seedling growth stages under salt stress, and showed better tolerance to salt environment. Therefore, Wangwenxiang could be used as an alternative salt tolerant germplasm resource.